Apparatus for arc welding

ABSTRACT

There is described herein an apparatus which facilitates electric arc welding either underwater or under adverse atmospheric conditions. This apparatus includes a housing chamber having three primary apertures therein. The first and second apertures are disposed oppositely of each other. A piston-like, hollow insert is adapted to be coaxially positioned in the first aperture. A transparent viewing member is disposed in the first aperture and held in place by the insert. A contact gasket is removably secured to the periphery of the second aperture to provide a seal between the work piece to be welded and the housing. A flexible sealing gasket is secured over the third aperture and is adapted to sealingly receive the welding gun. Finally, there is a means for introducing a shielding gas into the chamber to maintain it substantially free of the fluids from the surrounding environment during the welding operation. In underwater applications the welding electrode is held by a welding gun having a hollow guide tube which supports the welding electrode. A gas valve in the welding gun permits the entry of a gas under pressure to be introduced in the annular space within the guide tube about the welding electrode to permit a jet of gas to be used to clear the work area either when initially started or at other times during the welding process. Similarly, the welding current control switch is adapted to be surrounded by pressurized shielding gas to maintain it substantially water-free and thereby avert short circuits. A rocker arm mechanism is utilized to actuate the gas valve and the welding control switch such that either but not both may be actuated at a time. This is necessary to prevent the electrical arc from being blown out by the sharp blast of cleaning gas. The gun itself is formed of a solid member having various channels formed therein to provide for the necessary gas conduits and electrical wiring. Suitable end caps are placed over either end of the gun member to provide a water seal and to strengthen the gun.

United States Patent 1 Berghof 3,740,518 June 19, 1973 [73] Assignee:Anna Welding Corporation,

Orlando, Fla.

[22] Filed: Mar. 9, 1972 [21] Appl. No.: 233,071

[75] Inventor:

[52] US. Cl. 219/72, 219/74, 219/131 F,

219/139 [51] Int. Cl 823k 9/16 [58] Field of Search 219/72, 74, 73, 75,

219/147,l38,139,130,131,137,121EB [56] References Cited V UNITED STATESPATENTS 3,632,950 l/l972 Bcrghof 219/72 3,671,707 6/1972 Cunningham219/74 2,405,828 8/1946 Huguley 219/74 1,711,151 4/1929 Lincoln 219/743,659,076 4/1972 Ogden 219/74 1,746,207 2/1930 Alexander 219/742,590,084 3/1952 Bernard 219/72 2,459,812 l/l949 Griffiths 219/74FOREIGN PATENTS OR APPLICATIONS 446,035 8/1946 Italy 219/74 PrimaryExaminer-E. A. Goldberg Assistant ExaminerB. A. ReynoldsA!t0rneyMortenson & Weigel [57] ABSTRACT There is described herein anapparatus which facilitates electric arc welding either underwater orunder adverse atmospheric conditions. This apparatus includes a housingchamber having three primary apertures therein. The first and secondapertures are disposed oppositely of each other. A piston-like, hollowinsert is adapted to be coaxially positioned in the first aperture. Atransparent viewing member is disposed in the first aperture and held inplace by the insert. A contact gasket is removably secured to theperiphery of the second aperture to provide a seal between the workpiece to be welded and the housing. A flexible sealing gasket is securedover the third aperture and is adapted to sealingly receive the weldinggun. Finally, there is a means for introducing a shielding gas into thechamber to maintain it substantially free of the fluids from thesurrounding environment during the welding operation.

In underwater applications the welding electrode is held by a weldinggun having a hollow guide tube which supports the welding electrode. Agas valve in the welding gun permits the entry of a gas under pressureto be introduced in the annular space within the guide tube about thewelding electrode to permit a jet of gas to be used to clear the workarea either when initially started or at other times during the weldingprocess. Similarly, the welding current control switch is adapted to besurrounded by pressurized shielding gas to maintain it substantiallywater-free and thereby avert short circuits. A rocker arm mechanism isutilized to actuate the gas valve and the welding control switch suchthat either but not both may be actuated at a time. This is necessary toprevent the electrical arc from being blown out by the sharp blast ofcleaning gas. The gun itself is formed of a solid member having variouschannels formed therein to provide for the necessary gas conduits andelectrical wiring. Suitable end caps are placed over either end of thegun member to provide a water seal and to strengthen the gun.

11 Claims, 16 Drawing Figures Patented June 19, 1973 3,740,518

3 Shoal-Sheet 1 Pat ented June 19, 1973 3,740,518

3 skint-Sheet 5 II [2 F. L

cuzzl z' ws' APPARATUS FOR ARC WELDING BACKGROUND OF THE INVENTION3,632,950 issued Jan. 4, 1972 which is a continuationin-part of anapplication no. 701,700 filed January 30, 1968, now abandoned. Thisimprovement invention relates to apparatus useful in electric arcwelding in hostile fluid surroundings, including underwater, as wasdescribed in said Berghof patent and, more particularly, to gas shieldedunderwater electric arc welding using a consumable electrode.

At the present time underwater welds are achieved only with relativelygreat difficulty. In most cases, technique employed encompasses sinkinga caisson or chamber over the affected area or pipe to be welded,pumping the water from within the chamber and lowering the men andequipment into the chamber where the welding is performed. The men andequipment then are removed, water is allowed to re-enter the chamber andthe chamber finally removed. This procedure is not only time consumingbut is expensive.

Many efforts have been made to perform underwater welding using divingequipment. In the case of electric arc welding, coated, consumableelectrodes have been developed which when consumed shield the weldedarea sufficiently to permit a weld of sorts. Welds performed underwaterusing this technique, however, are generally unsatisfactory and not ofthe quality of welds obtainable above water.

It is, therefore, an object of this invention to provide an improvedapparatus which facilitates welding using consumable electrodes,particularly in hostile environments. Also, it is difficult to achievesatisfactory arc welds on land under adverse atmospheric conditions. Forexample, when the wind velocity exceeds 35 miles per hour most weldersare forced to stop work and wait for the wind to abate. The same is truein conditions of snow and rain during such conditions, quality weldingbecomes more difficult.

While the apparatus described in said earlier filed Berghof applicationis quite satisfactory for all of these applications, severaldifficulties were encountered. For one, the illumination of the workarea was somewhat less then desirable. In addition, it was discovered,due to the frequent need for replacing the viewing plate, that a farmore easily removable assembly was required. And, while commerciallyavailable guns of the type disclosed in said Berghof application couldbe modified for underwater welding applications, they were not entirelysatisfactory for underwater welding applications and often made the worksomewhat difficult.

Accordingly, it is another object of this invention to provide animproved welding gun for use in underwater welding applications.

An additional object of this invention is to provide an underwaterwelding apparatus having improved means for illuminating the weld areaand which is simply constructed and easily disassembled.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT According to the preferredembodiment of this invention, the apparatus for arc welding a work-piececomprises a housing chamber having means defining first and secondoppositely disposed apertures and a third aperture, a piston-like hollowinsert adapted to be positioned sealingly and removably in the firstaperture, a transparent viewing member adapted to be disposed over' thecross-section of the insert, a contact gasket adapted to be removablysecured to the periphcry of the second aperture, a flexible sealingjacket secured over the third aperture and adapted to sealingly receivea welding gun, and means for introducing a shielding gas into thechamber.

The preferred embodiment of the welding gun that is used with thischamber for supplying the electrode is a solid member having a pluralityof axial bores formed therein through which the shielding gas, weldingelectrode and electrical power are supplied. The welding electrode isfed through a guide tube which supports the electrode and provides anannular conduit about the electrode through which bursts of shieldinggas may be introduced for clearing the work area of the last remnants ofwater or dirt after the chambers shielding gas forces the water fromaround the work area. A

rocker arm type switch mechanism is provided which actuates either, butnot both, the gas control valve for supplying the burst of clearing gasor the electrical switch which controls the welding current to theelectrode. The welding current control switch is adapted to besurrounded by shielding gas to insure its insulation from leaking water.

Further, in accordance with the preferred embodiment of this invention alight source is positioned on the exterior of the chamber and adapted toshine directly through the viewing glass to illuminate the weld area ofthe work-piece. With this apparatus, the portable dry spot" or chamberof this invention, need merely be positioned with the contact gasketadjacent the work-piece and the shield gas supply turned on. This willforce the water from around the work area and from the chamber. At thispoint, the trigger may be depressed to supply a burst of clearing gas tothe work area after which the opposite end of the trigger may bedepressed to energize the welding current and the welding begins. As thewelding progresses the chamber is slid across the surface of thework-piece, always maintaining the weld area free of the hostileenvironment. The welding electrode has freedom of movement through theflexible sealing jacket to permit high quality welds even on underwaterobjects.

BRIEF DESCRIPTION OF THE DRAWINGS The invention, both as to itsorganization and method of operation, as well as additional objects andadvantages thereof, will be further understood from the followingdescription when read in connection with the accompanying drawings whichare not limitative and in which:

FIG. 1 is a back elevation view of the portable chamber and welding gunconstructed in accordance with this invention;

FIG. 2 is a side elevation view of the portable chamber and welding gunassembly illustrated in FIG. 1;

FIG. 3 is a plan view of the portable chamber illustrated in FIG. 1;

FIG. 4 is a front elevation view of the portable chamber illustrated inFIG. 1;

FIG. 5 is a cross-sectional view of the chamber illustrated in FIG. 1taken along the section lines 5-5;

FIG. 6 is a partial cross-sectional view of the portable chamber andwelding gun illustrated in FIG. 1 taken along the section lines 66;

FIG. 7 is a fragmentary cross-section view of a lighting assemblyillustrated in FIG. 1 taken along the section lines 7-7;

FIG. 8 is a fragmentary pictorial view of the removable tip and guidetube used to support the consumable electrode used herein;

FIG. 9 is a front end view of the welding gun illustrated in FIG. 1;

FIG. 10 is a cross-sectional view of the welding gun illustrated in FIG.1 taken along the section lines 10l0;

FIG. 11 is a back end view of the welding gun illustrated in FIG. 2;

FIG. 12 is a pictorial representation of the wire feed unit andassociated welding current and gas supply apparatus necessary tocomplete a welding system;

FIG. 13 is a partial elevation view of a contact gasket constructed inaccordance with this invention for use in welding along inside corners;

FIG. 14 is a plan view of the contact gasket illustrated in FIG. 13;

FIG. 15 is an elevation view of a contact gasket useful in weldingconvex surfaces; and

FIG. 16 is a plan view of the contact gasket illustrated in FIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As was taught in thesaid earlier filed Berghof application, electric arc welding may beaccomplished even in hostile environments such as underwater providedthat the welding electrode and the weld area of the work-piece areshielded from such hostile environment by utilizing an appropriateshielding gas. More specifically, an electric arc is drawn between anelongated consumable electrode and the work-piece. This are is protectedfrom the surrounding hostile environment such as water by a flowingstream of shielding gas. The shielding gas may be any of those gasessuitable for use as a welding atmosphere such as carbon dioxide andincludes the inert gases, helium, neon, argon, crypton, xenon and radon.The electrode preferably is inserted into and used in a movable housingchamber which is located at the end portion of the welding gun. Withinthis portable or movable housing chamber the weld area itself can beviewed more easily by the operator to facilitate his making high qualitywelds under the various hostile environments noted.

To facilitate the description, the welding apparatus of this inventionwill be described in conjunction with a total system capable ofachieving such results. To some extent the system described herein isthe same as that described in said earlier filed Berghof application. Inthis system there is a suitable source of electric power together withthe suitable source of the welding gases which together are denoted bythe block 16 (FIG. 12). This source may include suitable equipmentresting on the deck of a boat or barge on the surface of the water orunderwater adjacent the weld area. For simplicity of description thisinvention will be described in an under water environment. The linesrunning from the power and gas source 16 include a shielding gas line18, a control cable 20 which couples back to the welding equipment tocontrol the application of welding current. Power cable 22 supplies thenecessary power to the portable wire feeding unit 24 (FIG. 12). Thereare also two welding current cables 26 and 28 and finally a squirter gasconduit 30. All of these wires and cables together may be enclosedwithin a canvas sheath 32 for protection. The sheathed wires and cablesenter the wire feed unit 24 through guide rings 36 at one end. Suitablemeans such as sealing grommets are used to maintain a seal about thewires and cables and the interior of the portable wire feeder 24 free ofwater.

The portable wire feeder 24 may be a box-like structure completelysealed having a side plate 34 which is sealed by a suitable gasket (notshown) and held to the remainder of the wire feeding unit by appropriatebolts 38. Suitable gripping bars 40 may be secured to the exterior ofthe wire feeding unit 24 to facilitate its being picked up and carriedwhile in use.

Of the several input cables and conduits 18, 20, 22, 26, 28 and 30,three 18, 20 and 22, connect to the interior of the wire feeder 24whereas the remaining three the welding current cables 26 and 28 and thesquirter gas supply conduit 30 pass straight through the portable wirefeeder 24. Thus, the shield gas supply conduit 18 aides in maintainingthe interior of the wire feeder pressurized by the squirter gas. Thecontrol cable 20 connects with a conventional time delay mechanism topermit the wire feed to start prior to the application of the weldingcurrent. The power cable 22 supplies power for the conventional wirefeeder (not shown) within the wire feeder unit 24 as well as suppliespower for the light wire on the portable welding chamber as will bedescribed hereinafter. The wire feeder itself is not shown herein asnoted but may be any of the conventional wire feeding units that arecommercially available for the purpose of slowly playing out the weldingelectrode to the gun unit. The wire feeder is controlled withconventional controls which include a wire speed control knob 44 and aninch button 46. The inch button permits the electrode to be played outwithout the application of the welding current.

From the portable wire feeder 24 some seven cables emerge, all beingsealed as they pass through the wall of the wire feeder by suitablegrommets or the like (not shown) to prevent the leakage of water intothe feeder 24. Thus, there is a welding current control cable 20 whichpasses on to a welding gun 50 (FIG. 10). The control cable is connectedto a trigger switch in the welding gun and functions to activate thewire feed in the portable wire feeder 24 and to apply welding currentfrom the basic supply unit 16 to the welding electrode. The weldingcurrent itself is supplied through the cable 26 and the ground cable 28'is connected to a replaceable ground lug which is attached by welding tothe workpiece. There is a light wire 56 carrying an appropriate voltage,usually 12 or 24 volts, to the light 166 (FIG. 7) on the portablehousing chamber 10 as will be described hereinafter. The shielding gasis coupled through a shielding gas supply conduit 18' to the welding gun50 as is the squirter gas supply conduit 30 and a wire feed hose 60within which is enclosed a consumable electrode 14. In like manner theconduits and cables issuing from the portable wire feeder 24 may begathered together in a canvas sheath 32 for protection as they extend tothe welding gun 50. The hoses may be constructed of suitable rubberizedor plastic flexible material, reinforced if necessary to withstand thegas pressures. The cables may likewise be of any suitable type capableof electrically insulating the electrical current carrying wires.

The welding gun 50 (FIG. 1) is constructed preferably of a solidcylindrical piece of material. Any suitable rigid, non-conductingplastic is suitable for this purpose. The cylinder has a plurality ofaxially disposed bores therein to accommodate the several input cables,hoses and conduits 18, 20', 26', 30', 56 and 60 from the wire feeder 24.The shielding gas conduit 18 connects to a bore 62 in the welding gun 50which communicates with a shielding gas control valve 66 in the gun. Thevalve couples the gas through an orifice in the periphery of the weldinggun 50 through a shielding gas conduit 68 to the housing chamber 10. Thevolume of the wire feeder 24 acts as a surge tank to insure an adequatesupply of shield gas at high pressure. Thus, it is seen that the housingchamber is removably attached to the welding gun by the conduit 68 andprovides an annular nozzle or chamber about the welding gun electrode 14as will be described.

As the electrode 14 leaves the wire feeder it passes into a liner 67which is encased in a hose 60. The hose is attached to the end cap 70 ofthe gun as will be described. The liner 67 which may be a protectivespiral of stainless steel wire to prevent breakage of the electrode,goes through end cap 70 and fits into a counterbore 75 in a tubularinsert 74 in turn fitted into an axial bore 77 in the gun 50. The liner67 may be supported from contact with end cap 70 as it passes throughend cap 70 with a suitable insulating grommet (not shown). The tubularinsert 74 may be formed of copper or other good electrical conductor andis connected to the welding power cable 26 as by soldering or brazing toa lug 27 on the insert 74. Since the electrode 14 contacts the insert 74at many points as it progresses therethrough,

it receives energy through the energized copper tubing. In the frontportion of the welding gun the tubular insert 74 extends into a curvedbarrel assembly 76 for the electrode 14. Suitable jam nuts 69 may securethe end caps 70 and hose 72 to the ends of the welding gun. The frontend of the barrel assembly 76 terminates with an interior thread toaccommodate a replacable tip 81 which guides the end of the electrode14. The tip 81 has exterior threads such that it may easily be screwedinto or out of the barrel assembly 76. The sheath 32 is secured over therear end cap 70 by a clamp 71. An epoxy coating 97 may be placed overthe front end of the barrel assembly 76 to electrically insulate it fromthe water.

The squirter gas supply conduit 30' is coupled through an axial passage73 in the gun to a gas control valve 78 positioned in a recess in theside of the welding gun. This valve 78, when its stem 80 is depressed,permits gas under pressure to flow through an angular conduit 82 (dottedlines) formed within the welding gun from the valve 78 into the smallerannular space 83 surrounding the electrode 14 within the copper tubing74. To this end, the bore in the front end of the tubing 74 is slightlyenlarged by a counterbore to accommodate the flow of the squirter gasdirectly through insert 74 and the barrel assembly 76 and thereplaceable tip 81 to eject a stream of gas directly at the weld area.Thus, in the initial start up of the welding, this gas may be applied toclear the area of any debris, extraneous water, etc.

A welding current control switch is recessed in a second cavity withinthe side of the welding gun 50 in axial alignment with the squirtervalve 78. The axial passage 73 extends to the recess for the switch 90so that the squirter gas pressure maintains the switch substantiallyfree of water. Both the squirter valve 78 and the welding control switch90 are actuated by a rocker arm type trigger 92 which is recessed in anaxial peripheral slot 87 in the welding gun and pivoted at 94 such thateither the welding control switch 90 or the squirter valve 78 isactuated but not both. The depression of the welding control switch 90by the rocker arm, of course, actuates the wire feed and transmits acontrol signal back to the power source through the control cable 20 toenergize the welding current.

The light wire 56 passes through a bore in the welding gun and out thefront side adjacent to the shield gas valve 66 and terminates in abayonet-type plug (FIG. 1) which may be plugged into the light assembly102 of the housing chamber 10 as will be described.

The housing chamber 10 for the welding electrode 14 is constructed to begenerally of a hollow cylindrical shape with either end of the housing10 defining an aperture or opening having a particular function. Thus,the lower end of the housing (FIG. 3) has a transparent viewing plate122 (FIG. 5) to permit the operator to view the weld area. The viewingplate 122 is disposed in the lower portion of the housing 10 at an anglewith respect to the axis of the housing. This permits any water, weldingparticles, dirt, etc. to fall to the bottom, i.e., the lowermostextremity of the plate away from the central portion of the viewingplate 122. At this extremity a vent, aperture or orifice 124 ispositioned. The orifice 124 is threaded on the interior portion as at126 to accommodate a male threaded end 130 of a vent tube 132. The venttube itself is L-shaped and has an open end and typically may be in theorder of A inch to 7. inch in diameter to permit the escape of gas,water, welding particles, etc. as will be described hereinafter.

The viewing plate 122 is secured in a removable manner by forming acounter bore 131 within the housing chamber. On the inner portion of thecounter bore 131 is positioned an annular support ring 142 which has oneend chopped at an angle to hold the glass at the desired angularposition. The desired angular position typically is at a 20 angle withrespect to the axis of the cylinder in a preferred embodiment, althoughgreater or lesser angles may be used as desired. As a practical limit,however, this angle should be restricted to something greater than 0 andless than 70. Angles in excess of 70 cause more reflection and decreasethe viewers ability to view the weld area. A sealing gasket 144 ispositioned on the opposite side of the viewing plate 122 from thesupport 142. The gasket may be formed of rubber or other flexiblematerial capable of providing a pressure seal. The gasket in turn isheld in position by an annular insert 146 one end of which is formed atan angle complementary to the support 142. The insert 146 is made of adiameter slightly smaller than that of the support 142 and is slipfitted into position. This facilitates the removal and replacement ofthe viewing plate 122. Both the support 142 and insert 146 may be madeof metal or plastic as may be desired. A conventional spring-loaded,offset latching member 150 is mounted in the annulus 148 and ispivotable to hold the insert 146 in place and thereby contain theviewing plate 122 in a sealed position within the unit.

The other end of the housing chamber 10 is seen to have an internalshoulder portion 160 adapted to accommodate a sleeve which sleeve 162may be removably inserted and fitted in the housing chamber 10 to besupported by the shoulder 160. Peripheral slots 161 (seen most clearlyin FIGS. 13 AND 15) are formed in the periphery of the sleeve 162 sothat it may be removably secured by wingnuts 163 in the chamber walls. Aflexible gasket 164 is attached to the end face portion of the sleeve162 to permit its contact with the welding work-piece, thereby tosurround the immediate weld area and protect the electrode 14 from thewater or other surrounding environment. The sleeve 162 may be formed ofany metal or plastic as may be desired, although metal is preferredbecause of the proximity to the weld area. Although this gasket 164 maybe formed of any suitable flexible material, preferably a porous rubbersuch as foam rubber or plastic is used. With a porous material, when thechamber 10 is pressurized, the shield gas may bubble through the gasketmaterial and thereby prevent water from entering. This bubbling actionalso facilitates and serves to lubricate the movement of the gasket andthe chamber 10 across the work-piece as the welding is accomplished. Ingeneral, however, any suitable flexible material capable of providing agood contact with the work-piece may be used.

A light assembly 102 is attached to the insert 146 to direct lightenergy from the lamp 166 contained therein through the viewing plate 122thereby to directly illuminate the weld area. A small shield 168prevents the light from shining directly into the eyes of the welder andthereby obscuring his vision. The shield and the light socket arepreferably formed integrally to permit their removal for easyreplacement of the light bulb. The light assembly 102 is adapted toreceive the bayonet plug 100 of the light wire. The light assembly 102is preferably located approximately 135 from the vent aperture 124 suchthat its light is directed toward the more recessed portion of theviewing plate 122, thereby creating less light reflection into the eyesof the weldor. In some applications it may be desireable to recess thelight well within the insert 146 such that the light is closer to theviewing plate 122, thus reducing reflections. The light assembly is onlyillustrated as being exteriorly mounted for clarity of illustration.

To complete the housing chamber 10, radial apertures or openings 200 and202 may be formed typically in one or both opposite walls of thecylindrical housing chamber 10. The orifice or opening 200 formed in thelower wall (as seen in FIG. 1 of the drawing) is adapted to permit theentry of the welding barrel 76. A short tubular extension 201 may jointhe aperture 200. A flexible sealing jacket 204 is fitted over thisextension and held in position by a suitable retaining member 206 whichmay be in the form ofa clamp. For this purpose it is preferred that theextension 201 be a short tubular section which may be moldedcontiguously with the housing 10 and radially disposed of the housingchamber 10. The flexible sealing jacket 204 should have a small centralorifice to accommodate the barrel assembly 76 and permit the barrel tobe pivoted relative to the aperture to permit ready freedom of movementin and about the work area.

Diametrically opposite the flexible seal gasket is the entry point forthe shield gas supply. This entry point may be essentially interior ofthe chamber as from the tube 68. Preferably the shield gas supply tube68, as noted, is coupled in through a male fitting (not illustrated)adapted to engage a female orifice 210 within the side wall of thechamber 10. This orifice 210 couples the shield gas through an innerconduit 212 formed within the wall of the housing chamber itself to aringlike radial diffuser 214 which is fitted into the aperture 202 andsecured by a suitable adhesive, or welded if the chamber is metal. Thisradial diffuser 214 has a U- shaped cross-section and inner radiallydisposed openings 216. so that gas may diffuse form the annulus formedby the U-shaped cross-section slowly into the housing chamber 10 fromall points of the inner circumference of the diffuser 214 and therebyprovide a smooth flowing path of the shielding gas without causing anyhigh velocity gas streams which could cause a disturbance and cloud ofwater and/or welding particles and thereby impair the view of thewelder. The diffuser 214 may be formed of two members, namely, theU-shaped annular trough-like member and a top plate 218 which enclosesthe diffuser. These members are secured together as by an adhesion orwelding depending on the material employed.

In operation, the housing chamber 10 is positioned over the area to bewelded with the gasket in contact with the weld area. Next, the shieldgas control valve 66 is turned on such that shield gas can now enter thechamber and force the water in the case of underwater welding therefrom.The rear portion of the trigger 92 on the welding gun 50 is depressedand a burst of squirter gas passes through the annular space between theelectrode 14 and the tip 81 thereby clearing the immediate area to bewelded of any final droplets of water or particles remaining. Next, thefront end of the trigger 92 is depressed thereby energizing the wirefeed unit and the welding current and the weld proceeds. During thisoperation, the contact gasket is maintained in close contact with thesurface of the work area as the weld progresses. The friction betweenthe weld area and the contact gasket 64 is reduced by the bubblingshield gas through and around the gasket.

It is noted, as was described in the said Berghof patent, that the venttube 132 which is rotatable is maintained in a horizontal position solong as the weld is overhead. During the time that the weld is on avertical surface, the vent tube is maintained in a position slightlydownward from the horizontal position. Similarly, when the weld is beingaccomplished on the top surface, the vent is maintained in a downwardposition with respect to the surface. The adjustment of this vent tubeby its rotation aids in controlling the amount of shield gas that isdischarged through the vent tube and may be adjusted as necessary by thewelder.

The shielding gas that is preferred will vary as a function of the depthunder the surface. Thus, at the surface, almost pure carbon dioxide (COmay be used. However, as the weld depth increases to 50 and feet andmore in depth, a mixture of at least 80 percent argon and 20 percent COwill produce a better weld. At intermediate depths, as the weld depthdecreases, the ratio of argon in the mixture is decreased. At extremedepths the proportion of argon approaches percent and can equal 100percent as the depth increases beyond 100 feet. Each welder preferablywill make his own adjustments to meet his own welding technique andrequirement. If desired, a pressure sensor 84 (FIG. 9) may be placed inthe front end of the gun 50 and used to transmit pressure measurementsback to the gas supply to automatically vary the gas ratios. Other gasesand gas mixtures may also be used as noted hereinbefore, however, theabove noted mixture is preferred.

It was earlier noted that when welding an overhead surface, residualwater as well as welding particles tend to fall onto the viewing plate.Because of the sloping surface of the viewing plate, these particlesfall to the bottommost extremity of the housing where they are easilypassed out due to the flowing shield gas through the vent tube. Theangles of the viewing plate are preferred to be between 20 and 60 withrespect to the axis. Extremely acute angles tend to obstruct the weldersvision due to refraction and also reflection of the light. Conversely,angles approaching 90 do not permit the welding particles to fall offthe viewing plate and, hence, are not desirable, else the weldingparticles would tend to accumulate and block the vision of the welder.

In alternative embodiments of the invention the gasket is givendifferent configurations to conform to the particular surface beingwelded. Thus, for a cylindrical work-piece, such as a pipe, the sleeve162 and flexible gasket 164 may have a concave curvature in its plane(as illustrated in FIGS. and 16) to conform to the exterior of the pipe.Other configurations are particularly desirable for interior andexterior corners and the like. Thus, in FIGS. 13 and 14 a flexiblesealing gasket is mounted on a sleeve 162. The sleeve is illustrated asbeing shaped to weld an inside corner on the workpiece.

While the welding gun and its associated housing have primaryapplication in the field of underwater electric arc welding, it is to benoted that they may also be used on land under hostile environmentalconditions such as in high wind, rain, snow, and the like to protect theweld area and permit satisfactory welds to be accomplsihed,Alternatively, the portable chamber may be used with the stickelectrodes in underwater applications although this is not preferredover the feed-type electrodes.

There has thus been described a unique, improved apparatus primarily forunderwater arc welding. This apparatus has many advantages including aremovable viewing plate, a readily replaceable illuminating light thatis formed external to the housing chamber for ready replacement. Also,an integrated squirter gas jet is provided directly from the tip of thewelding electrode to insure accurate direction for removal of unwantedparticles. Furthermore, the welding control switch within the weldinggun itself is pressurized by the gas pressure of the shielding gassupply which flows in and about the electric switch. A unique rocker armtype trigger permits selective application of either the welding currentor the squirter gas.

While the invention has been disclosed herein in connection with certainembodiments and certain structural and procedural details, it is clearthat changes, modifications or equivalents can be used by those skilledin the art; accordingly, such changes within the 6 principles of theinvention are intended to be included within the scope of the claimsbelow.

What is claimed is:

1. Apparatus for electric arc welding of a work-piece comprising:

a housing chamber having means defining first and second oppositelydisposed apertures and a third aperture,

a piston-like hollow insert adapted to be positioned sealingly andremovably in said first aperture,

a transparent viewing member adapted to be supported by and disposedacross the cross-section of said insert, whereby said viewing member isremovably positioned in said first aperture,

said first aperture being cylindrical and defined by a bore andcounterbore forming an inner shoulder adapted to receive said insert,said insert having non-parallel end faces and being adapted to fitwithin said counterbore.

means defining an exhaust port in the well of said chamber contiguoussaid viewing member, thereby to facilitate removal of foreign matterfrom said viewing member,

a contact gasket adapted to be removably secured to the periphery ofsaid second aperture, thereby to provide at least a partial seal betweensaid workpiece and said housing,

a flexible sealing jacket secured over said third aperture adapted tosealingly receive a welding electrode, and

means for introducing a shielding gas into said chamber.

2. Apparatus according to claim 1 wherein said means for introducingshield gas includes:

means defining a fourth aperture in said chamber,

and

diffusing means for diffusing said gas through said fourth aperture intosaid chamber, thereby to avoid distributing unwanted particles throughsaid chamber.

3. Apparatus according to claim 1 which also includes illuminating meanspositioned externally of said chamber and adapted to direct light energythrough said first aperture and said viewing member to said work-piece.

4. Apparatus according to claim 1 which includes a guide tube forhousing said electrode, and sealed means for introducing gas underpressure through said guide tube directly to the work area as a jet forclearing the same of water and other undesirable matter.

5. Apparatus according to claim 4 which includes a removable nozzle tipadapted to be fitted onto the end of said guide tube, thereby to housesaid electrode.

6. Apparatus according to claim 4 which also includes:

a welding gun means adapted to mount said guide tube and pass saidelectrode therethrough, said gun means housing a welding current controlswitch, and

means for surrounding said switch with said shielding gas.

7. Apparatus according to claim 6 wherein said gun means includes:

a gas control valve for controlling said jet of gas from said guidetube, and

an externally located rocker arm having one end adapted to actuate saidcontrol switch, whereby either but not both of said gas control valveand said control switch may be actuated at the same time.

Apparatus according to claim 7 wherein said gun means is adapted to besupplied with said shielding gas under pressure, and which alsoincludes:

conduit means for supplying shielding gas directly to saidhousing'chamber, and

a second valve means for controlling the flow of said shielding gasthrough said conduit means.

Apparatus according to claim 1 which also includes:

welding gun means to control the passage of said electrode to saidwork-piece and the application of electrical energy to said electrode,

said gun means housinga welding current control switch for controllingthe application of said electrical energy to said electrode, and

means for surrounding said switch with said shielding gas.

10. Apparatus for the underwater electric arc welding of a work-pieceusing a welding electrode comprising:

housing chamber having means defining first and second oppositelydisposed apertures and a third aperture,

transparent viewing member adapted to be removably positioned in saidfirst aperture,

a contact gasket adapted to be removably secured to the exteriorperiphery of said second aperture, thereby to provide at least a partialseal between said work-piece and said housing,

means for introducing a shielding gas into said chamher,

a flexible sealing jacket secured over said third aperture, adapted tosealingly receive said welding electrode, thereby to facilitateshielding the work area of said work-piece and said welding electrodefrom said water using said shielding gas,

a guide tube for housing said electrode, and sealed means forintroducing gas under pressure 11. Apparatus according to claim 10wherein said gun means includes:

a gas control valve for controlling the flow of gas through said guidetube, and

an externally located rocker arm having one end adapted to actuate saidgas control valve and the other end adapted to actuate said controlswitch, whereby either but not both of said gas control valve and saidcurrent control switches may be actuated at the same time.

1. Apparatus for electric arc welding of a work-piece comprising: a housing chamber having means defining first and second oppositely disposed apertures and a third aperture, a piston-like hollow insert adapted to be positioned sealingly and removably in said first aperture, a transparent viewing member adapted to be supported by and disposed across the cross-section of said insert, whereby said viewing member is removably positioned in said first aperture, said first aperture being cylindrical and defined by a bore and counterbore forming an inner shoulder adapted to receive said insert, said insert having non-parallel end faces and being adapted to fit within said counterbore. means defining an exhaust port in the well of said chamber contiguous said viewing member, thereby to facilitate removal of foreign matter from said viewing member, a contact gasket adapted to be removably secured to the periphery of said second aperture, thereby to provide at least a partial seal between said workpiece and said housing, a flexible sealing jacket secured over said third aperture adapted to sealingly receive a welding electrode, and means for introducing a shielding gas into said chamber.
 2. Apparatus according to claim 1 wherein said means for introducing shield gas includes: means defining a fourth aperture in said chamber, and diffusing means for diffusing said gas through said fourth aperture into said chamber, thereby to avoid distributing unwanted particles through said chamber.
 3. Apparatus according to claim 1 which also includes illuminating means positioned externally of said chamber and adapted to direct light energy through said first aperture and said viewing member to said work-piece.
 4. Apparatus according to claim 1 which includes a guide tube for housing said electrode, and sealed means for introducing gas under pressure through said guide tube directly to the work area as a jet for clearing the same of water and other undesirable matter.
 5. AppaRatus according to claim 4 which includes a removable nozzle tip adapted to be fitted onto the end of said guide tube, thereby to house said electrode.
 6. Apparatus according to claim 4 which also includes: a welding gun means adapted to mount said guide tube and pass said electrode therethrough, said gun means housing a welding current control switch, and means for surrounding said switch with said shielding gas.
 7. Apparatus according to claim 6 wherein said gun means includes: a gas control valve for controlling said jet of gas from said guide tube, and an externally located rocker arm having one end adapted to actuate said control switch, whereby either but not both of said gas control valve and said control switch may be actuated at the same time.
 8. Apparatus according to claim 7 wherein said gun means is adapted to be supplied with said shielding gas under pressure, and which also includes: conduit means for supplying shielding gas directly to said housing chamber, and a second valve means for controlling the flow of said shielding gas through said conduit means.
 9. Apparatus according to claim 1 which also includes: a welding gun means to control the passage of said electrode to said work-piece and the application of electrical energy to said electrode, said gun means housing a welding current control switch for controlling the application of said electrical energy to said electrode, and means for surrounding said switch with said shielding gas.
 10. Apparatus for the underwater electric arc welding of a work-piece using a welding electrode comprising: a housing chamber having means defining first and second oppositely disposed apertures and a third aperture, a transparent viewing member adapted to be removably positioned in said first aperture, a contact gasket adapted to be removably secured to the exterior periphery of said second aperture, thereby to provide at least a partial seal between said work-piece and said housing, means for introducing a shielding gas into said chamber, a flexible sealing jacket secured over said third aperture, adapted to sealingly receive said welding electrode, thereby to facilitate shielding the work area of said work-piece and said welding electrode from said water using said shielding gas, a guide tube for housing said electrode, and sealed means for introducing gas under pressure through said guide tube directly to the work area as a jet for clearing the same of water and other undesirable matter and welding gun means to mount said guide tube and pass said electrode therethrough, said gun means housing a welding current control switch, and means for surrounding said current control switch with said shielding gas.
 11. Apparatus according to claim 10 wherein said gun means includes: a gas control valve for controlling the flow of gas through said guide tube, and an externally located rocker arm having one end adapted to actuate said gas control valve and the other end adapted to actuate said control switch, whereby either but not both of said gas control valve and said current control switches may be actuated at the same time. 